People value things. In capitalism, the ones who value them the most, and who are able to pay, get them.

That's not limited to capitalism, lol.

If you disrupt this mechanism

What mechanism? You haven't described a mechanism.

by allocating resources differently, you risk that resources are wasted.

Do you not think capitalism itself wastes vast amounts of resources? Have you seen a landfill? How about the humans, including children, that subsist on that waste? The absurdity of so many things that are produced?

You should really read more on this topic. You seem to be stuck in simplistic all-or-nothing thinking. The idea that waste could exist is not itself something anyone should be concerned about. There is no reason to think it won't always exist. The question is what are the material impacts.

Of course you can use other allocations but is that a good idea?

Yes.

Capitalism has many flaws, e. g. monopolies disrupt this mechanism

Still haven't described a mechanism. Maybe you're attempting to understand Baby's First Utility and Pricing argument? I assure you nothing you've said is new to me.

but it just has to be better than its competitors to survive.

What has to be better than its competitors to survive? Define better.

You imagine taking over capitalism and allocating luxeries differently. I doubt that those luxeries will exist. If workers only want to work e.g. 8 hours per week, because socialism, the surplus will be gone.

This is because you don't understand the basic mechanisms of production nor economic systems nor history. Your doubts mean nothing because you have never investigated this topic.

While understanding the origins of surplus requires that you go read, I'll give two examples of how absurd this is that are easy to understand.

The first is that capitalism is extremely inefficient and destructive. Duplicating bureaucracy across businesses, overproduction problems, regular recessions, deliberately inflated unemployment, ripping people's lives apart for short term profit (if you don't care about people's lives, which you should, you can at least understand that destroying someone's ability to work for 40 years because of some 2-year minimum wage stint is bad), chaos in productive direction, blowing resources on fundamentally pointless exercises (the vast majority of marketing and insurance activities), the list goes on. But that's just inefficiencies. Capitalism also requires destruction. The Grapes of Wrath tells a visceral - and common - story of this at human scale (the destruction of stock to address a profitability crisis), but the greatest destruction is through war and financial domination between countries, i.e. imperialism. Capitalism creates crisis and incentives that resolve through the killing of millions by direct murder and by deprivation. Looking at only the British Raj is sufficient to understand this, but it is actually worldwide and constant.

The second is that capitalism has become dominated by finance and speculation, which are drags on production. Humans overpaying for goods and services because debt cost has been thrust upon them, and not merely personsl debt like a credit card, but the actual inflated cost of things likes housing, healthcare, insurance. And, more, because it is dominant, it controls policy, feeding human lives into its maw to shit out dollars.

If you can make those workers work more under socialism without a gun to their head, then you should be able to do so right now within the legal framework of a coop.

We are in Fisher-Price pretend land, now. This is beginning to feel like talking to a child that thinks their pretend play is just as valid as your knowledge.

You're gonna have trouble understanding this topic if you can't get past that kind of behavior. It keeps you from seeking knowledge. A kind of self-coddling, producing a false sense of certainty and unearned smugness.

Sidequestion: how does a member of the bourgeoisie without capital look like?

They're either not bourgeois or we need to split a hair to talk about control and ownership being a dual character of one thing: dominant power over the means of production. The bourgeoisie are slaves to the capitalist system as well, they adopt its psychology and carry out its dictates. They are just in the oppressor role and benefit accordingly.